Trouble Removing HP Connected Allowed Senders

I'm having some trouble removing an email from my 'Allowed Senders' list. From the HP Connected settings page (HP Connected > Devices > Settings (under the appropriate product) > Manage Allowed Senders), I get the message 'Unable to remove the email address from the list' when clicking to remove the second of the three addresses shown in the image below.

Has anyone seen anything like this? Any ideas on how to fix it? I tried making the second address the owner and then switching it back to see if that would shake anything loose, but no luck.